CVE-2019-0937
📋 TL;DR
This is a remote code execution vulnerability in Microsoft Edge's Chakra JavaScript engine that allows attackers to execute arbitrary code by exploiting memory corruption when handling objects. It affects users running vulnerable versions of Microsoft Edge on Windows systems. Successful exploitation could lead to complete system compromise.
💻 Affected Systems
- Microsoft Edge
📦 What is this software?
Chakracore by Microsoft
Edge by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the victim's system, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Browser compromise allowing attacker to execute code in the context of the current user, potentially stealing credentials, session cookies, and sensitive data accessible through the browser.
If Mitigated
Limited impact due to browser sandboxing and modern exploit mitigations, potentially resulting in browser crash rather than successful code execution.
🎯 Exploit Status
Memory corruption vulnerabilities in JavaScript engines typically require sophisticated exploitation techniques to bypass modern mitigations like ASLR and DEP.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Microsoft Edge version with May 2019 security updates
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0937
Restart Required: Yes
Instructions:
1. Open Windows Update settings. 2. Check for updates. 3. Install all available security updates. 4. Restart the system to complete installation.
🔧 Temporary Workarounds
Disable JavaScript
windowsDisable JavaScript execution in Microsoft Edge to prevent exploitation
Use Alternative Browser
allSwitch to a different browser until patches are applied
🧯 If You Can't Patch
- Implement application whitelisting to prevent execution of unauthorized code
- Deploy enhanced monitoring for suspicious browser behavior and memory corruption attempts
🔍 How to Verify
Check if Vulnerable:
Check Microsoft Edge version in Settings > About Microsoft Edge. If version is older than May 2019 updates, system is vulnerable.Check Version:
msedge://settings/helpVerify Fix Applied:
Verify Windows Update history shows May 2019 security updates installed and Microsoft Edge version is updated.📡 Detection & Monitoring
Log Indicators:
- Browser crash events with memory access violation codes
- Unusual JavaScript execution patterns
- Process creation from browser context
Network Indicators:
- Connections to known malicious domains from browser process
- Unusual outbound traffic patterns
SIEM Query:
EventID=1000 OR EventID=1001 SourceName='Application Error' AND ProcessName='MicrosoftEdge.exe' AND FaultingModuleName='chakra.dll'